1. Field of the Invention
The present invention relates to fasteners, and more particularly to a hinge connecting a lamp head and a lamp stand of, for example, a table lamp.
2. Description of Related Art
In a variety of conventional lamps, the projecting angle of a lamp is generally adjusted by means of a hinge connecting a lamp head with a lamp stand. Electric wires extend from the lamp stand through the hinge to reach the lamp head.
Referring to FIG. 4, a related lamp hinge (not labeled) comprises a first connector 29 and a second connector 11 pivotably connected to the first connector 29 connecting with a lamp head (not shown). The first connector 29 is integrally formed at a top of a lamp pole 20 which has a bottom end for connecting with a lamp stand (not shown). The second connector 11 can rotate relative to the first connector 29. The lamp pole 20 comprises a pair of shells 21, 22. The second connector 11 comprises a pivotal portion 15 pivotally received in the first connector 29. The pivotal portion 15 evenly forms three protruding portions 17, 18, 19 circumferentially distributed at a side thereof. Each protruding portion 17, 18, 19 has a cylindrical configuration. The protruding portions 17, 18, 19 are pivotally received in a groove 220 of the first connector 29. During assembly of the lamp, electric wires of the lamp extend through a gap between the protruding portions 17, 18 or between the protruding portions 18, 19. As the second connector 11 rotates relative to first connector 29, the electric wires may be abraded by the protruding portion 18 located between the protruding portions 17, 19. Furthermore, because of limited contact area between the protruding portions 17, 18, 19 and the first connector 29, the protruding portions 17, 18, 19 are prone to wear and a lifespan of the hinge of the lamp will be reduced.
There is thus a need to provide a hinge for a lamp which will not abrade the electric wires when the hinge is rotated, preferably with a robust structure to extend product lifetime.